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<a name="Variadic-Pointer-Args"></a>
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<a name="Pointer-Arguments-in-Variadic-Functions"></a>
<h3 class="section">6.25 Pointer Arguments in Variadic Functions</h3>
<a name="index-pointer-arguments-in-variadic-functions"></a>
<a name="index-variadic-functions_002c-pointer-arguments"></a>

<p>Standard C requires that pointer types used with <code>va_arg</code> in
functions with variable argument lists either must be compatible with
that of the actual argument, or that one type must be a pointer to
<code>void</code> and the other a pointer to a character type.  GNU C
implements the POSIX XSI extension that additionally permits the use
of <code>va_arg</code> with a pointer type to receive arguments of any other
pointer type.
</p>
<p>In particular, in GNU C &lsquo;<samp>va_arg (ap, void *)</samp>&rsquo; can safely be used
to consume an argument of any pointer type.
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